Hydraulic paper cutter and clamp



INVENTOR JOHN A. MAL/W E- .3 BY dm,m w9m,wa

ATTORNEYS July 1, 1969 J. A. MALM 3,452,630-

HYDHAULIC PAPER CUTTER AND CLAMP Filed Oct. 10, 1966 INVENTOR JOHN A.MAL M ATIORNHS United States Patent U.S. Cl. 83380 9 Claims ABSTRACT OFTHE DISCLOSURE A paper cutter having a self-contained power and controlunit for operation of the cutter and clamp piston-cylinder assemblieswhich includes a reservoir with a pump therein, a motor and flywheelmounted on one side of the reservoir driving the pump, a pair ofsolenoid control valves mounted on the opposite side of the reservoirfor controlling the cutter and clamp, respectively, such valves beinginterconnected by a line extending interiorly of the reservoir, andfluid lock means for the respective pistoncylinder assemblies whichincludes pilot operated check valves, the pilot lines of each beingconnected to the opposite ends of the piston-cylinder assemblies.

This invention relates generally as indicated to a paper cutter and moreparticularly to an improved drive and control system for an automatichydraulic paper cutting machine.

Hydraulic paper cutting machines have well-known disadvantages in thatthey are oftentimes noisey, and the hydraulic system is subject toleakage. The latter problem may result in spoiled work, since oil orhydraulic fluid in the work area will damage the paper. Also, due tofluid leakage or seepage (when the machine is shut down for a fairlylong period of time, such as a weekend, the seepage may permit thecutting edge of the knife to drop below the clamp in its elevatedposition. With the blade thus slightly projecting, an incautiousoperator may cut the back of his hand.

Attempts have been made to prop the blade in elevated positionmechanically as seen, for example, in US. Letters Patent No. 3,111,876to Rupp, but these require a multiplicity of parts which are subject towear.

Moreover, hydraulic systems for paper cutting machines are notoriouslydiflicult to service since the components must generally be replacedindividually, these being at the back of the machine beneath the table.

In spite of the disadvantages of hydraulic paper cutting machines, suchmachines are far superior to a manual or mechanical machine.

It is accordingly a principal object of the present invention to providea hydraulic paper cutting machine not having some of the above-noteddisadvantages.

Another principal object is the provision of a hydraulic paper cuttingmachine which incorporates in the hydraulic system safety lockingdevices precluding both the binder and knife from moving from theirretracted position until the start of the cut cycle.

Another object is the provision of a hydraulic paper cutting machinehaving a compact easily serviceable power unit.

A further object is the provision of a hydraulic paper cutting machinewhich is not as subject to the disadvantages of leaking and noise asconventional machines.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail a certain illustrativeembodiment of the invention, this being indicative, however, of but oneof the various ways in which the principle of the invention may beemployed.

In said annexed drawings:

FIG. 1 is a rear elevation of a machine in accordance with the presentinvention;

FIG. 2 is an enlarged fragmentary vertical section of the power driveunit seen in FIG. 1;

FIG. 3 is a schematic diagram of the hydraulic circuit in the neutralposition;

FIG. 4 is a hydraulic schematic showing the system in its out condition;and

FIG. 5 is a similar hydraulic schematic showing the return condition.

Referring now to the annexed drawings and more particularly to FIG. 1,it will be seen that the illustrated paper cutting machine comprises afabricated frame 1 which supports a table 2 extending both rearwardlyand forwardly of the frame 1. The table 2 extends through the lower edgeof a window 3 in the frame and the rear of such table pendantly supportsdrive motor 4 for back gauge 5. Movement of the back gauge toward andaway from the viewer as seen in FIG. 1 is obtained by a screw extendinglongitudinally of the table 2 and driven by the transmission withinhousing 6.

A binder clamp B is mounted for vertical movement in gibs at each sideof the window 3, and each end of the clamp B is supported on links asshown at 8 and 9 which are connected at their lower ends to cranks 10and 11, respectively, mounted on transverse binder operating shaft 12which is journalled at the opposite sides of the frame 1 as shown at 13and 14.

Another crank 15 is secured to the shaft 12 to which is connected therod 16 of binder piston-cylinder assembly 17. The blind end of suchassembly is pivoted at 18 to bracket 19. In operation, thepiston-cylinder assembly 17 is extended to rock the shaft 12 to pulldown the links 8 and 9 to cause the binder B to move downwardly in itsgibs to clamp a stack of paper on the table 2. The binder is mounted forvertical movement just to the rear of the knife K.

The knife K is removably adjustably mounted in a knife holder 21 whichis supported by links 22 and 23 pivoted at 24 and 25, respectively, tothe holder 21. The links 22 and 23 are also pivoted at 26 and 27,respectively, to the frame 1 above the window 3.

The link 22 extends beyond and upwardly from the pivot 24 with the knifeholder 21 and the outer end is pivoted at 28 to the rod 29 of the knifepiston-cylinder assembly 30. The blind end of the assembly 30 is pivotedat 31 to bracket 32 secured between gussets 33 in the verticallyextending side housing 34. In operation, the assembly 30 is retracted tocause the knife to swing downwardly and to the right about the pivots 26and 27.

The power unit for the assemblies 17 and 30 is mounted beneath the table2 at the rear of the machine and is visible through access opening 36.Such power unit is shown generally at 37.

The power unit includes a sub-base 38 releasably connected to the mainframe 1 so that the entire unit may readily be pulled from the machine.Supported on the subbase 38 is a tank 39 of generally rectangularconfiguration and on the interior wall thereof there is mounted ahydraulic pump 40 with the drive shaft 41 thereof projecting through thewall and being connected by coupling 42 to flywheel 43 mounted on thedrive shaft 44 of the pump motor 45. The motor 45 is mounted on bracket46 cantilevered from the exterior of the same wall on which the pump 40is mounted.

On the opposite wall of the tank 39 there are mounted control valves 48and 49 for the binder cylinder 17 and the knife cylinder 30,respectively. Such valves may be of the double solenoid, three positiontype with the valve 48 having a blocked center or neutral position whilethe valve 49 has an open center or neutral position.

As seen perhaps more clearly in FIGS. 2, 3, 4 and 5, the pump 40includes an inlet 50 connected to filter 51 near the top of the tank 39and the outlet 52 is connected to a pressure relief valve 53. From theoutlet, the fluid pressure lines are connected to the valve 49 which isin turn connected to the valve 48 through the line 54. From the valve49, lines 56 and 57 lead to the blind and rod end of the cylinder 17,while from the valve 48, lines 58 and 59 lead to the blind and rod endsof the cylinder 30. As seen in FIG. 1, pilot operated check valves 60and 61 are provided in the lines 57 and 58, respectively, adjacent therod end of the binder cylinder assembly 17 and the blind end of theknife cylinder assembly 30, respectively. The respective pilot lines 62and 63 operating the valve 60 and 61 are connected across to the lines56 and 59, respectively, leading to the blind end of the binder cylinderassembly 17 and the rod end of the knife cylinder assembly 30,respectively.

The purpose of the pilot operated check valves 60 and 61 adjacent to theblind end of the knife assembly 30 and the rod end of the binderassembly 17 is to lock the hydraulic fluid in such cylinders to precludemovement of the knife and binder downwardly unless and until hydraulicpressure is applied to the opposite ends of the respective assemblies.Accordingly, if fluid leaks or seeps from the lines 58 or 57 due toleakage about the pump, for example, the position of the knife or theposition of the binder cannot change. It is only when the pressure isactuated by energization of the valves 48 and 49 that the knife orbinder clamp can be moved.

In operation, the neutral position shown in FIG. 3 will first obtain.The operator then places a stack of papers on the table 2 and the backgauge is energized by the motor 4 to move the papers to the properposition which is determined by the operator by scale tape 65 driventhrough shaft 66 which moves across an illuminated gauge at the front ofthe machine. When the stack of papers is in the proper position, the cutcycle is ready to start. The operator will have at the front of themachine two widely positioned push buttons, thus requiring the presenceof both hands, by which the cut cycle is started. The closing of thesepush buttons energizes the binder down solenoid of the valve 49 shiftingthe valve to the schematic position shown in FIG. 4 extending thepistoncylinder assembly 17. This brings the binder clamp B down upon thestack of papers behind the knife and it is again noted that the binderclamp cannot move until pressure is applied to the line 56 and throughthe pilot line 62 to open the pilot operated check valve 60. As soon asthe pressure switch 67 dictates, the knife down solenoid of valve 48will be energized shifting the valve to the position shown in FIG. 4.This then causes the knife cylinder assembly to retract bringing theknife down to the completion of its cutting stroke.

On the return stroke, the directional valves 48 and 49 will be shiftedtothe position seen in FIG. 5 withpressure being supplied through thecheck valves 60 and 61 in lines 57 and 58 to the rod end of the cylinderassembly 17 and the blind end of the cylinder assembly 30. The extensionof the cylinder assembly 30 elevates the knife to its retracted positionand the safety pilot operated check valve 61 will preclude accidentalretraction of the assembly and thus lowering of the knife due to fluidleakage.

It can now be seen that there is provided an improved hydraulic papercutting machine which incorporates in the hydraulic system unique safetyfeatures. Moreover, the compact power unit provides an easilyserviceable, less noisy drive which will maintain the working area ofthe machine much more free of hydraulic fluid or oil deposits.

Other modes of applying the principles of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I, therefore, particularly point out and distinctly claim as myinvention:

1. A hydraulic paper cutter including a knife cylinder assembly and abinder cylinder assembly, a tank having a bracket extending from oneside thereof, a drive motor and flywheel mounted on said bracket, a pumpin said tank driven by said motor flywheel, and valve means mounted onanother side of said tank operative to control said knife and bindercylinder assemblies, said valve means comprising a pair of directionalvalves operative to supply hydraulic pressure to the opposite ends ofsaid knife and binder cylinder assemblies.

2. A paper cutter is set forth in claim 1 including a pilot operatedcheck valve in the hydraulic line connected to the blind end of saidknife cylinder assembly.

3. A paper cutter as set forth in claim 2 wherein the pilot lineoperating said pilot operated check valve is connected to the rod end ofsaid knife cylinder assembly.

4. A hydraulic paper cutter as set forth in claim 1 including a filterand relief valve in said tank as well as plumbing connections betweensaid pump and valves whereby to minimize fluid leakage.

5. A hydraulic paper cutter including a knife cylinder assembly and abinder cylinder assembly, a tank having a bracket extending from oneside thereof, a drive motor and flywheel mounted on said bracket, a pumpin said tank driven by said motor flywheel, valve means mounted onanother side of said tank operative to control said knife and bindercylinder assemblies, and pilot operated check valves mounted on saidknife and binder cylinder assemblies operative to preclude movementthereof prior to actuation of said valves.

6. A hydraulic paper cutter as set forth in claim 5 wherein the pilotoperated check valve is connected to the rod end of the binder cylinderassembly and to the blind end of the knife cylinder assembly.

7. A hydraulic paper cutter including a knife, a pistoncylinder assemblyoperatively connected to said knife, a binder, a piston-cylinderassembly operatively connected to said binder, valve means operative tocontrol the movement of said piston-cylinder assemblies, and fluid lockmeans between said valve means and said pistoncylinder assembliesoperative to preclude movement of said knife or binder toward the workwithout actuation of said valve means, said fluid lock means comprisingpilot operated check valves for the respective pistoncylinderassemblies, the pilot lines of the respective check valves beingconnected to the opposite ends of said piston-cylinder assemblies.

8. A hydraulic paper cutter as set forth in claim 7 including a powerunit for said piston-cylinder assemblies comprising a tank, a drivemotor and flywheel mounted on one side of said tank, a pump in said tankdriven by said motor and flywheel, said valve means being mounted on theopposite side of said tank.

9. A hydraulic paper cutter as set forth in claim 8 including a filterand relief valve in said tank as well as the plumbing connectionsbetween said pump and valves whereby to minimize fluid leakage.

References Cited UNITED STATES PATENTS Riddle 83380 Seybold et a1. 83390Barley 83380 Hill et al 833 80 ANDREW R. JUHASZ, Primary Examiner. 5FRANK T. YOST, Assistant Examiner.

US. Cl. X.R. 83390, 639

